Variation with redshift of the ratio between the X-ray and SZ flux (left panel) and between Y_X and (right panel). Line: locus established from scaling relations (Planck Collaboration 2011e; Arnaud et al. 2010). The dotted lines correspond to a factor of two above or below the mean relation. Black points: data for new Planck candidates confirmed with XMM-Newton. Colour points: data for clusters with ambiguous X-ray redshift estimates, one colour per cluster. Each point corresponds to one of the redshift solutions for an individual cluster, as derived from the χ²(z) minima (see Fig. 10).